Method for forming dough barrier

ABSTRACT

A horizontal chamber and a piston movable in the chamber to discharge potato dough through a discharge opening at one end of the chamber. A dough dividing structure adapted for mounting in the discharge opening. A diaphragm and means for mounting the diaphragm on the face of the piston such that when the piston is retracted in the chamber from a body of dough therein, an air passage is created to relieve the vacuum between the diaphragm and the dough, thereby avoiding distortion of the dough. For charging the chamber with a body of dough to form an impervious barrier therein there is an adapter in vertical alignment below the constituent introducing devices; the adapter supports the piston and the cylinder in vertical alignment below the constituent introducing devices so as to expedite charging of the machine to form an impervious dough barrier. After the constituents set into a dough the chamber, with the impervious barrier therein, and the piston are installed in the machine for normal operation. An improved nozzle for introducing the water constituent which nozzle virtually eliminates all kinetic energy or velocity necessarily developed when the water is delivered to the nozzle.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 507,602,filed Sept. 19, 1974 and now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to method and apparatus for forming shaped potatobodies, such as french fry shaped pieces, by reconstituting dry potatoagglomerates with water to form a dough and then by shaping the doughinto appropriate shaped pieces.

2. Description of the Prior Art

U.S. Pat. No. 3,622,355 discloses an agglomerated potato product thatcan be rehydrated into a potato dough by addition of water thereto andwithout substantial physical agitation. U.S. Pat. Nos. 3,605,647 and3,771,937 disclose apparatus for automatically rehydrating theagglomerated potato product into a dough and forming it into french fryshaped pieces of uniformly high quality.

SUMMARY OF THE INVENTION

The present invention provides improvements in the above noted prior artteachings which enhance the quality and uniformity of the product, andsimplify the operation and maintenance of the apparatus employed to formthe product.

The above noted U.S. Pat. Nos. 3,605,647 and 3,771,937 disclose anapparatus in which a plurality of thin wire strands span the dischargeopening of a chamber; when potato dough is moved from the chamberthrough the spaces between the strands, it is divided into strips whichare then transversely separated to form french fry shaped bodies. Asexplained in the U.S. Pat. No. 3,605,647 , it is desirable that the openarea between the strands occupies a substantial proportion of the totalarea of the discharge opening so that the dough can be moved through theopening without applying substantial pressure thereto.

Another object of the present invention is to simplify the formation ofan impervious barrier within the chamber which barrier is essentialduring automatic operation of the apparatus wherein water and dry potatoagglomerates are deposited in the chamber and must there be retaineduntil the constituents set into a firm self-supporting dough.Achievement of this object can best be appreciated by comparing thetechniques disclosed in the aforecited patents. In the U.S. Pat. No.3,605,647 a body of dough, equal in volume to a full dough charge isretained in the chamber. A special adapter plug of equivalent volume isnecessary in charging the apparatus after the same has been cleaned. TheU.S. Pat. No. 3,771,937 discloses an externally disposed seal plate andlinkage for moving the seal plate into and out of sealing relationshipof the discharge opening. By way of contrast, the present inventionprovides a piston supporting stud in vertical alignment below theconstituent introducing devices in the apparatus. Thus, to charge theapparatus in order to form an impervious barrier, the piston is removedfrom its operating rod and placed on the stud, the chamber is placedover the piston in a vertical orientation, the constituents areintroduced into the chamber, the constituents are permitted to set intoa dough, and then the piston and chamber are reassembled in their normaloperative positions in the apparatus for regular operation.

A feature and advantage of achieving the last stated object is that theadapter plug structure on the one hand and the seal plate and itsoperating linkage on the other hand are eliminated so that the machineis simplified and there are no loose parts to be cleaned or otherwisecared for.

A further object of the present invention which also tends to simplifyand expedite automatic operation of the machine is to preserve theintegrity of the impervious dough barrier when the piston is retractedpreparatory to receiving a charge of dry product and water thereinto.Because the dough body is substantially impervious and somewhat moist,and because the piston of necessity is sealed in its movement within thechamber, a vacuum can form on retraction of the piston away from thedough body, which vacuum can distort or destroy the integrity of thedough body. According to the present invention, the piston is providedwith a flexible impervious diaphragm on the face thereof. The diaphragmis secured to the piston at only one location so that portions of thediaphragm remote from such location can separate from the piston andfrom the dough body. The piston has one or more airvents therethroughwhich are sealed when the diaphragm lies against the piston surface butwhich are opened when the diaphragm is pulled away from the pistonsurface, as it is during retraction of the piston and diaphragm from thedough charge. Thus, the integrity of the impervious barrier formed bythe dough body is not adversely affected when the piston is withdrawn,because the vacuum tending to form as a consequence thereof is almostimmediately relieved.

Yet another object of the present invention is to provide a water nozzlewhich introduces water into the chamber without significant kineticenergy or velocity so as to avoid turbulence within the dry productwhich would, unless compensated for, tend to produce nonuniform wettingof the dry product. As described in the U.S. Pat. No. 3,771,937, wateris delivered from a heating tank to the nozzle through a pump which ofnecessity imparts substantial kinetic energy to the water. Such kineticenergy is almost totally dissipated by the nozzle of the presentinvention, which nozzle includes inner and outer concentric tubularmembers, an inlet at one end of the inner tubular member, openings atthe top of the inner member for affording a flow of water into theannular space between the two members and relatively large area openingsat the bottom of the outer member for discharging the water from thenozzle. The water that is supplied to the inner tubular member withsubstantial kinetic energy exits the slots in the outer tubular memberby the force of gravity and without substantial kinetic energy.

A feature and advantage of the nozzle of the present invention is thatit can introduce a substantial quantity of water into the chamber in ashort time and without significant kinetic energy or velocity whichwould tend to result in nonuniform wetting of the dry product in thechamber.

The foregoing, together with other objects, features and advantages,will be more apparent after referring to the following specification andaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of dough forming and shaping apparatus,portions being broken away to reveal internal details.

FIG. 2 is a view similar to FIG. 1 with the dough chamber in a positionto afford charging the same with an initial quantity of dough to form animpervious barrier within the chamber.

FIG. 3 is a view taken along line 3--3 of FIG. 1.

Fig. 4 is a view taken along line 4--4 of FIG. 1 and showing themechanism for mounting the piston onto the piston rod.

FIG. 5 is a cross sectional view taken along the line 5--5 of FIG. 4.

FIG. 6 is a plan view of the improved nozzle of the present inventiontaken along line 6--6 of FIG. 1.

FIG. 7 is a cross sectional view taken along line 7--7 of FIG. 6.

FIG. 8 is a longitudinal cross sectional view of the nozzle taken alongline 8--8 of FIG. 7.

FIG. 9 is a cross sectional view of the nozzle taken along line 9--9 ofFIG. 8.

FIG. 10 is a cross sectional view of the nozzle taken along line 10--10of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring more particularly to the drawings, reference numeral 12indicates a machine for forming and shaping potato dough into french fryshaped pieces. Except in the particulars described in detailhereinafter, apparatus 12 is substantially identical to that disclosedin U.S. Pat. No. 3,771,937. The apparatus includes an imperviouscylindrical chamber 14 that is open at both ends to define a dischargeopening 16 and a rear opening 18. The rear portion of the upper wall ofcylindrical chamber 14 defines an inlet opening 20 through which inletopening the dry potato agglomerate and water constituents are introducedfor forming dough according to the invention. Slidably disposed withincylindric chamber 14 is a piston indicated generally at 22 which isfastened to an operating rod 24 that is driven in reciprocation towardand away from discharge opening 16 via a drive mechanism 26. Because thedrive mechanism is substantially as disclosed in the U.S. Patent No.3,771,937 , it will not be described in detail herein.

Apparatus 12 includes a rigid horizontal wall 28 from which depend apair of spaced apart mounting brackets as shown in FIG. 3 at 30.Brackets 30 define slots 32 which confront one another in horizontalalignment across the space between the brackets to receive identicalmounting lugs 34 that are rigid with the exterior surface of chamber 14and are adapted to be slidably received within the slots. The slots eachhave an abutment (not shown) rearward of the front surface of brackets30 for establishing the proper position of mounting lugs 34 and chamber14 in the apparatus. On the front surface of each bracket 30 is a headedpin 36 which affords rigid mounting to the machine of a dough dividingstructure generally indicated at 38. Dough ejected through doughdividing structure is separated from the dough within chamber 14 by atransverse separator 39 which is driven in windshield wiper fashionacross the exterior of dividing structure 38.

Dough dividing structure 38 includes a cylindric flange 40 which definesan interior opening adapted to fit snugly on the exterior diameter ofcylinder 14. Extending in diametrical opposition outward of flange 40are two identical mounting ears 42 which define keyhole shaped openings44 adapted for engagement over pins 36 so that upon rotation of thestructure 38 the entire structure can be quickly inserted onto andremoved from the apparatus. Mounting ears 42 have finger grips 46 tofacilitate the same. The elements are so proportioned that dividingstructure 38, when engaged with pins 36, retains chamber 14 in itsoperative position.

Integral with cylindric flange 40 is a plurality of thin elongatemembers or strands 48 which span the opening defined by the flange inparallel spaced apart relation. Strands 48 are uniformly spaced apartfrom one another by a distance corresponding to the thickness of thefrench fry shaped pieces formed by the apparatus, typically about 1/4inch more or less.

The upper and lower regions of dividing structure 38 have integralimpervious wall portions 53 which terminate at inward tapering edges 54that extend parallel to strands 48. Wall portions 53 eliminate formationof sliver-like potato pieces and reinforce the structure.

In order to remove a dividing structure 38 and chamber 14 for cleaning,as is necessary after a full day's operation in a restaurant or likeenvironment, it is only necessary to rotate the dividing structure so asto align the relatively large portion of keyhold shaped openings 44 withpins 36. Thereupon the dividing structure is removable as is the chamberby sliding the chamber axially until lugs 34 are clear of slots 32.Because piston 22 contacts the potato dough, it too must be removed forcleaning. FIGS. 4 and 5 disclose the connection or latch between piston22 and rod 24 which affords such removal.

Piston 22 includes a latch part on the rear surface thereof. The latchpart, including a transverse wall 56, which is spaced from the rearsurface 58 of the piston to define a slot therebetween. As seen in FIG.4, wall 56 is excised to define an upward opening channel bounded by asemicircular lower edge portion 60 and two parallel vertical edgeportions 62 that are tangent to the semicircular edge portion.

There is a similar shaped but larger slot between wall 56 surface 58;the larger slot is bounded by a semi-circular lower edge portion 64 andtwo parallel vertical edge portions 66 that are tangent to semicircularedge portion 64. The latch part on the rear of piston 22 is completed bya protuberance 68 extending inward from the upward extremity of one oftangential edge portions 62.

There is a complemental latch part on the outer end of rod 24. See FIG.5. Adjacent the forward or outer end of rod 24 there is formed a groovehaving a semicircular surface portion 70 that corresponds to surfaceportion 60 and from which extend mutually parallel tangential surfaceportions 72 which correspond with tangential edge portion 62 of the slotdefined in the rear surface of piston 22. Piston slot surfaces 62 engagerod slot surfaces 72 to establish the position of the piston on the rodand prevent relative rotation.

Because piston 22 is molded in a unitary structure from suitablethermoplastic material such as nylon, it has a degree of resilience.Accordingly, the piston can be inserted onto and removed from the end ofrod 24, because the material yields sufficient to permit protuberance 68to distort during such insertion and removal.

The front face of piston 22 is rimmed by a relatively thin integral lip74, which because of its thinness and because piston 22 is constructedof nylon or the like is sufficiently flexible to form a substantiallywatertight or sealing relationship with the inner wall of chamber 14.Inward of lip 74 is an annular groove 76. Inward of annular groove 76the piston has a planar surface 78 which is spaced in an axial directionbehind the axial extremity of lip 74. A flexible diaphragm 80 restsagainst planar surface 78 at its central region and has an annularprojection 81 which is shaped complementally to groove 76 so as to fitsnugly therein.

For securing diaphragm 80 to piston 22 there is integral with thediaphragm a rearward extending post 82 which has a radially outwardextending protuberance 84 spaced from the rear face of the diaphragm byan amount corresponding to the thickenss of the piston. The wall of thepiston defines a slot 86 which is sized to receive post 82. Thediaphragm, post and protuberances are made of rubber so that there issufficient deformability to permit insert of the post through slot 86.It will be noted that post 82 and slot 86 are spaced remote from theaxial centerline of the piston so that the remote portion of diaphragm80 is free to separate from the planar surface 78 of the piston.Adjacent slot 86 the wall of the piston defines one or more airventopenings 88, which airvent openings are closed by diaphragm 80 when thediaphragm rests against planar piston surface 78. This constructionpermits the piston to be moved rearward away from contact with a body ofdough within chamber 14 because the lower portion of diaphragm 80 pullsaway from planar surface 78 in response to retraction of the piston soas to establish an air path through openings 88, between the diaphragmand the piston, and around the edge of the piston.

As explained in somewhat more detail in the above noted patents, doughis formed within chamber 14 by introducing thereinto a quantity of drypotato agglomerate through a chute 90 and water through a nozzle 92. Animpervious barrier spanning discharge opening 16 is essential to retainthe constituents within the chamber until the water has been absorbedinto the potato agglomerate and the mixture has set into a firm dough.According to the present invention a body of dough 93 is retained inchamber 14 to define the barrier during normal operation of theapparatus. The barrier has an axial dimension or thickness of about 11/2inches which in one system designed according to the invention is equalto about one-half the thickness of a full charge of dough. After theapparatus has been cleaned, it is essential to form an initial charge ofdough within chamber 14 so that the impervious barrier is present forsubsequent machine operations. For this purpose apparatus 12 includes abase plate 94 below the chamber and its associated parts. Secured tobase plate 94 in vertical alignment below dry product chute 90 and waternozzle 92 is a piston supporting stud 95. The piston supporting stud hasadjacent the surface of base plate 94 a cylindric portion having adiameter corresponding to semi-circular edge portion 60 of the slot inpiston 22. At the upper end of such cylindric portion stud 95 has alarger cylindric portion which has a diameter corresponding tosemi-circular surface 64 in the piston slot. Accordingly, the pistonwhen removed from rod 24 can be engaged with stud 95 so as to supportthe piston, face up, in vertical alignment below chute 90 and nozzle 92.Because base plate 94 has a horizontal planar surface surrounding stud95 and because the rim of cylinder 14 that defines discharge opening 16resides in a plane transverse of the axis of the chamber, the chamberwhen placed upon the piston 22 is supported by base plate 94 in avertical position with rear opening 18 in vertical alignment below dryproduct chute 90 and nozzle 92. See FIG. 2. The dry product and waterdelivery system can then be activated in a normal fashion and becausecylinder 14 and piston 22 are in vertical alignment below chute 90 andnozzle 92, the constituents will be deposited into chamber 14. Thepotato agglomerates are uniformly wetted, and after a suitable timeinterval (e.g. 30 - 90 seconds) a firm dough D is formed in the chamber.The dough has sufficient firmness that when chamber 14 is raised upward,the dough will remain in the chamber, there being no vacuum therewithinby virtue of the presence of diaphragm 80 as described above. Thechamber is set aside; piston 22 is disengaged from stud 95 and isinstalled on rod 24 by interengagement of the latch members describedabove. Then chamber 14 is installed by engaging lugs 34 in slots 32after which dividing structure 38 is secured. The machine is thenoperated to dispense half the initial dough charge through dischargeopening 16. The dough mass remaining within the chamber constitutesimpervious barrier 93 for formation of subsequent batches of dough.Accordingly the need for extra plugs or seal plates is eliminated withthe advantage of simpler cleaning and freedom from concern about looseparts.

In normal operation, i.e. after the chamber 14 has been initiallycharged, the dry product and water are introduced through inlet opening20 into chamber 14 which is disposed in the horizontal orientation shownin FIG. 1. In order to effect uniform wetting of the dry product, firstthe dry product is introduced through chute 90 and then water issupplied through nozzle 92. In order for the correct quantity of waterto be introduced through nozzle 92 in a short period of time, water issupplied to the nozzle via a pump as more fully disclosed in U.S. Pat.No. 3,771,937. It is not desirable however that the water be sprayed athigh velocity since such impairs the uniform distribution of the waterthroughout the dry product. According to the present invention nozzle 92is constructed so that the velocity or kinetic energy present at theinlet of the nozzle is dissipated within the nozzle whereby the soleforce acting on the water as it exits the nozzle is the force ofgravity. Moreover, the water is distributed uniformly across thetransverse dimension of the chamber. A nozzle for achieving thisdesirable mode of operation is shown in FIGS. 6 - 10. The nozzlegenerally includes an inner rigid tube 96 and an outer tube 97 mountedconcentric with the inner tube and sized to define an annular spacetherebetween. The water is introduced through a conduit or pipe 98 intothe inner tube whereupon it flows through holes in the inner tube thatdefine passages to the annular space between the inner tube and theouter tube. Because the volume of the annular space is substantialcompared to the volume of the inner tube, virtually all the velocity orkinetic energy in the water is dissipated and the water falls by gravitythrough openings provided in the outer tube.

Inner tube 96 defines a central opening of circular cross section whichconverges or tapers slightly from the inlet to which pipe 98 isconnected to the end remote from the inlet end. Accordingly, thepressure is substantially constant along the central opening of innertube 96. Radiating outward from the exterior surface of inner tube 96are circular discs 100 and 102 which support outer tube 97 relative tothe inner tube and divide the volume between the inner and outer tubesinto three longitudinally spaced chambers identified respectively inFIG. 8 at 104, 106 and 108. Chambers 104 and 108 are of substantiallyequal volume and chamber 106 is of relatively smaller volume. The upperportion of the outer surface of inner tube 96 that is within chambers104, 106 and 108 defines a horizontal surface 110, which extendschordally of the nozzle center-line. As can be seen most clearly in FIG.9 the length of the chord is somewhat less than the diameter of thecentral opening of inner tube 96. The presence of chordal surface 110not only enlarges the volume of chambers 104, 106 and 108, but definesthe location for the passages that extend from the inner opening of tube96 to the chambers between the inner and outer tubes. The longitudinaledges of chordal surface 110 form a convenient line to form such holes.Extending into chamber 108 there are six holes 112 that, as can be seenin FIGS. 8 and 10, extend vertically and are disposed at the edge ofchordal surface 110. The holes are symmetrical of the center line sothat water passing therethrough loses substantial velocity in impingingon the upper region of the inner surface of outer tube 97. The holesinto chamber 104 are identified at 114 and can be eight in number. Holes114 are formed adjacent opposite edges of chordal surface 110 and aredisposed in pairs uniformly spaced along chamber 104. Into centralchamber 106 there are two holes 116 of relatively larger diameter. Thenumber and location of holes 112, 114 and 116 is such that the water isintroduced into chambers 104, 106 and 108 in accordance with thelongitudinal dimension of the respective chambers. The water flowsaround the annular space between the inner and outer tubes as shown inFIGS. 9 and 10, and loses whatever residual velocity it may still havebecause of the relatively large volume of the annular spaces.

There are three outlet openings corresponding respectively to volumes104, 106 and 108, the outlet openings being identified as 104a , 106aand 108a. The outlets are formed at the bottom of outer tube 97 so as toassure that water flowing therefrom will flow downward into chamber 14.Openings 104a and 108a are substantially identical and have a lengthcorresponding to the lengths of the chambers with which theyrespectively communicate. In alignment with openings 104a and 108a theouter surface of inner tube 94 defines a V-shaped extension the sides ofwhich are tangent to the circular shape of inner tube 96 and the apex118 of which is in vertical alignment with the midpoint of outlet 108a.The V-shaped extension assists in dissipating any velocity remaining inthe water and guides it into movement in a downward direction throughoutlet 108a. Outlet 106a is circular in shape and discharges water fromchamber 106 with little or no velocity other than that due to the forceof gravity reacting on the water. Thus because the water is supplied toinner tube 96, conveyed upwardly through passages 112, 114 and 116 andthen downward through the annular chambers between the inner and outertubes it possesses virtually zero velocity, other than due to the forceof gravity, when it egresses through outlet openings 104a, 106a and108a. In addition, the water egressing the outlet openings isdistributed substantially uniformly along the length of nozzle 92; forexample in one device having the proportions of FIG. 8, twice as muchwater flows from each of openings 104a and 108a as flows from opening106a. Thus the nozzle of the present invention permits introduction of asubstantial quantity of water into chamber 14 in a short time and in auniformly distributed manner without significant kinetic energy orvelocity that could well adversely affect the uniformity of the dryproduct mass.

Although outer tube 97 functions as a unitary element, it is constructedof an upper part 97a and a lower part 97b for convenience ofconstruction and assembly. The parts of the outer tube are fixedtogether along a plane extending horizontally through the nozzle.

In describing the operation of the apparatus of this invention indetail, it will be assumed that the apparatus has been cleaned andrequires initial charging to form impervious barrier 93 within chamber14. First, diaphragm 80 is installed onto piston 24 by engaging post 82within slot 86. The piston is then engaged in a face-up relation ontostud 95 by engaging the large diameter portion of the stud into the sloton the rear surface of the piston. Cylinder 14 is placed over the pistonwith the discharge end 16 downward and the rear end opening 18 upward.When the rear end opening 18 is upward, inlet opening 20 will also beupward. Thereupon the apparatus is activated, whereupon it suppliespreselected amounts of dry product through chute 90 and water throughnozzle 92 into the chamber. As described in U.S. Pat. No. 3,622,355 theconstituents combine without mixing or agitation to form a relativelystiff potato dough. The setting time is in the range of about 30 secondsto 90 seconds, depending principally on the temperature of the watersupplied through nozzle 92.

When the dough has set, removal of chamber 14 from piston 22 and baseplate 94 will carry the dough mass with it. The charged chamber is setaside and piston 22 can be removed from stud 95 and installed onto rod24. The latching mechanism between the piston and rod assures correctorientation, i.e. with air vent passages 88 in the upper or top regionof the piston. With the piston in place, cylinder 14 is installed byengagement of lugs 34 in slots 32 and the assembly is completed byinstallation of dough dividing structure 38. See FIG. 3. The apparatusis then cycled and about one-half of the initial dough charge isdischarged through opening 16 for formation into shaped bodies bycooperation of dividing structure 38 and separator 39. There is then animpervious barrier 93 that spans discharge opening 16 so that formationof subsequent charges of dough can proceed. The dough is formed, asexplained in somewhat more detail in U.S. Pat. No. 3,771,937 byactivating the dry product and water supply systems to deposit dryproduct through chute 90 and water through nozzle 92 into the chamber.Piston 22 is then moved leftward as viewed in FIG. 1 to a position wherethe dry product and water are consolidated into a volume that extendfrom about the left hand extremity of inlet opening 20 to the surface ofimpervious barrier 93. The piston is retained in the consolidateposition at least until the constituents set into a firm dough.Thereafter when it is desired to dispense french fry shaped pieces, themachine is activated by the operator and piston 22 moves leftward tourge the dough through discharge opening 16 and the spaces betweenstrands 48. When the dough has been ejected by an amount correspondingto the thickness of a french fried piece transverse cutter 39 isautomatically activated to separate the projecting strips whereuponpiston 22 is caused to move forward another increment. Because of thelarge open area between the strands 48 of dividing structure 38 a smallamount of pressure is required.

The driving mechanism 26 is arranged so as to limit the forward mostmovement of piston 22 so as to retain in chamber 14 a dough body thatdefines impervious barrier 93. Thereupon piston 22 is retracted. Becauselip 74 of the piston forms a substantially airtight seal with thechamber wall and because impervious barrier 93 also creates an airtightseal, there is a tendency on reversal or retraction of piston 22 to forma vacuum between the piston and the impervious dough barrier. The firstconsequence of such vacuum is that diaphragm 80 tends to remain incontact with the rear surface of impervious dough barrier 93 and as seenin broken lines in FIG. 5 the region of diaphragm 80 remote from post 82pulls away from planar piston surface 78. Such movement continuous untilthere is opened an air passage through piston passage 88 behinddiaphragm 80 and around the edge of the diaphragm. As can be seen inFIG. 5, the outside diameter of diaphragm 80 is somewhat less than theinner diameter of chamber 14 so as to permit establishment of an airpassage around the periphery of the diaphragm. In any event when the airpassage is opened, the vacuum between the piston and the imperviousdough barrier is broken so that the piston moves rearward withoutadversely affecting the integrity of the dough barrier.

As the piston is moved rearward to the position shown in FIG. 5 and thenforward to the above mentioned "consolidate" position, dry product andwater are introduced into chamber 14 from chute 90 and nozzle 92. Thequantity of water, as more fully explained in U.S. Pat. No. 3,771,937,is metered by activating a pump for a preselected duration. Because thepump delivers water through pipe 98 to nozzle 92 at substantialvelocity, in order to deliver the required amount of water within areasonable time duration (about 2 seconds), the construction of nozzle92 in dissipating such velocity is important. The water enters thecentral passage in inner tube 96, passes upward through openings 112,114 and 116, and then falls down and around the outer surface of theinner tube for discharge through outlets 104a, 106a and 108a. Because ofthe construction of nozzle 92, the water is symmetrically distributedinto the chamber without significant velocity other than that due to theforce of gravity acting on the water. Accordingly, the water distributesitself uniformly throughout the potato agglomerate residing in thechamber. After the piston is moved to the "consolidate" position andafter a delay for the constituents to set into a firm dough, theapparatus is ready for forming and dispensing additional french fryshaped pieces.

When it is desired to disassemble the apparatus for cleaning, dividingstructure 38 is removed by disengaging keyhole slots 44 from pins 36.Removal of the dividing structure 38 permits removal of chamber 14,piston 22, and diaphragm 80. Because impervious barrier 93 is arelatively small volume, e.g. 11/2 inches in thickness, it can bediscarded without significant waste. The parts can then be thoroughlywashed, and cleanliness and long life is assured because the importantparts are of unitary construction formed from molded plastic.

Thus it will be seen that the present invention provides improved doughforming and shaping apparatus which in addition to being less complexthan similar apparatus described in the above noted patents is easier toclean, is superior in forming and shaping the dough and is far lessexpensive to manufacture. Moreover, because of the improved doughcharging arrangement provided according to the present invention thereare no loose parts which require care or storage.

Although one embodiment of the invention has been shown and described,it will be obvious that other adaptions and modifications can be madewithout departing from the true spirit and scope of the invention.

What is claimed is:
 1. An improved method for forming an imperviousdough barrier upon start up of a potato dough forming and shapingmachine comprising the steps of providing a machine having an elongatechamber of uniform cross section which defines a discharge opening and arear opening axially spaced from the discharge opening, the chamberhaving a side inlet opening adjacent the rear opening, mounting meansfor mounting the chamber in a substantially horizontal position with theside inlet opening in an upward position, devices in vertical alignmentabove the side inlet opening which form means for introducingpreselected amounts of dry potato agglomerates and water along avertical path into the chamber through the side inlet opening, a pistonsized for a fluid-tight sliding fit within the chamber, a piston rodextending into the chamber through the rear opening and mounted to thepiston to axially move the piston toward and away from the dischargeopening to extrude dough through the discharge opening, the piston rodoperating to terminate piston movement short of the discharge opening soas to retain in the chamber a dough mass constituting an imperviousbarrier for effecting formation of subsequent batches of dough from drypotato and agglomerates introduced through the side inlet opening, anddough shaping mechanism supported at the discharge opening for shapingthe dough into shaped pieces as the dough is extruded through thedischarge opening by the piston,disengaging the piston from the rod,supporting the piston in substantially horizontal orientation inalignment below the introducing devices, placing the chamber in an emptycondition with the discharge opening downward over the piston and in asubstantially vertical orientation so that the piston seals thelowermost opening of the chamber, activating the introducing devices todeposit into the chamber through the rear opening preselected quantitiesof dry potato agglomerates and water, maintaining the piston and chamberin position until the water has thoroughly wetted the potatoagglomerates so as to form a set dough sufficiently stiff to retain acharge of potato agglomerates and water in said chamber and installingthe chamber in horizontal relationship beneath the introducing devicesafter completion of said maintaining step, and extruding the stiff doughthrough the discharge opening, such that at least part of the stiffdough remains in the chamber after extruding the dough through thedischarge opening so as to afford formation of a subsequent dough chargewhile the chamber is in the horizontal position.
 2. A method accordingto claim 1 wherein said piston supporting step includes the step ofproviding a stud in vertical alignment below the introducing devices andengaging the piston on said stud.